📦 Product Management Interviews Part 2/4

Product Cases

Niki Birkner
11 min readSep 9, 2021

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There are three types of questions you can potentially get asked in a Product Case interview, in order of popularity:

  1. How would you design X for Y?
  2. How would you improve product X?
  3. What’s your favorite product and why?

I wrote a blog post ~ a week ago about the structure of the interviews, the screener and the take home assignment. Today, I present to you a list of frameworks that helped me answer these questions when I was preparing for my interviews. Although, as I mentioned in tip #3 of how to do well in any interview, you should avoid sounding robotic and relying solely on frameworks to get you to a coherent answer. Remember: “Everyone can memorize a framework, but not everyone can understand how to apply it in different scenarios.”

Design a product

The first, and most common, type of question you can get asked in a Product Case interview is: How would you design X for Y?, where X is the physical or digital product and Y is the audience. Here are some examples of what X and Y could stand for —

  • Design an Elevator for the Blind
  • Design an ATM for the Elderly
  • Design a Phone for the Deaf

Here’s the process I follow to answer this type of question:

  1. Questions & Assumptions
  2. Structure
  3. Goals
  4. Users and Customers
  5. Pain Points and Use Cases
  6. Current Product
  7. Potential Features
  8. Product Vision [Optional]
  9. Success Metrics [Optional]
  10. Wrap Up

Below you can find details on how to approach each of those points.

Questions & Assumptions

Ask questions and state assumptions up front. This will help show the interviewer that you are aware that you may need to make decisions with incomplete information, but you try to make the most informed decisions possible, a coveted quality of a PM. Once the interviewer reads the problem out loud, you will likely have plenty open questions and assumptions ready. However, in the case where you feel stuck, here are some questions and assumptions that can get you started:

  • [Question] Is there any specific customer segment we’re interested in targeting, or is that something you would like me to define?
  • [Assumption] I’m assuming that my target customers are mostly geographically located in the US, is that a fair assumption?
  • [Question] Are there any drivers behind this design decision? Should I just focus on the user experience? Are we trying to incorporate potential revenue opportunities in any way? Are we hoping to increase engagement?
  • [Assumption] It seems fair to assume that user engagement should be our north start objective, do you agree?
  • [Question] Any potential constraints, borders or boundaries?
  • [Assumption] For the purposes of this question, I’m only considering software solutions. Does that seem like the right choice to you?

Structure

Another positive characteristic of any good PM is that they communicate effectively to all audiences (customers, different stakeholders, etc.).

You’re likely to have already heard this public speaking advice:

Tell them what you are going to tell them, tell them, then tell them what you told them. — Dale Carnegie

What we’re talking about here is the “Tell them what you are going to tell them” part. You should walk your interviewer through the structure of what you‘re about to dive into (as quickly as possible). This will help them better follow what you’re saying and you better structure your thoughts. It will also make your whole answer more memorable. You should also enumerate your points, because as one of my mentors says: “humans think in numbers.” They’re more likely to remember all your points if you enumerate them.

✅ Do

Provide a crisp structure of what’s ahead

  • First I will talk about goals
  • Second I will brainstorm the users and their different use cases
  • Third I will list out some potential features
  • Fourth I will evaluate each of those features against the goals (tradeoffs)
  • Lastly, I will define some of the key metrics we will use to measure success

❌ Don’t

Use the same exact structure for two different problems presented by the same interviewer

Be married to your structure

Take a long time in this part

Users and Customers

Identify users and customers. Note that customers and users can be one but they can also be many.

  • Customer is the person paying for the product (e.g., if you’re building a toy for kids, the customers is the parent)
  • User is the person using the product (e.g., in the same example, the kid would be the user)

Depending on what type of company you work at, the user may also be the person paying, but there can also be someone else purchasing it for them (their organization, their school, their coaches, their insurance companies).

✅ Do

Briefly touch upon what each of the potential users AND customers are and what they care about

Say “I’m just taking a few notes as I talk through this” if you’re taking paper notes while you talk

Decide on one user group to dive into

Ask the interviewer for a few minutes to jot down pain points and use cases

❌ Don’t

Talk only about the obvious users

Talk only about the user you have already pre-selected

Select more than one user group (as this will make the next part more complex, and you’re likely to run out of time)

Pain Points and Use Cases

What are the use cases? Why are they using this product? What are their pains?

✅ Do

Say something along the lines of — “Just to clarify who I’m honing in on… I’m thinking about [users] and their goal is [state goal]. Thinking about some potential challenges/pain points for those user groups…”

List the different tasks or scenarios that a user might want to use the product for. Don’t think only about what they do with a product but why they do it. What is their underlying motivation?

Select 1–2 pain points from the 4–5 you enumerated that you will want to hone into

❌ Don’t

Discard pain points simply because they seem hard to solve for

Select more than 1–2 pain points; ideally it’s only 1 (again, this will make the next section less complex)

Current Product

How are customers solving their problems today? How well is the current product doing for their use case? Are there obvious weak spots?

There’s always a way in which customers or users are solving their problems, even though they might not be obvious.

For example, imagine you’re the Google Calendar PM, and you’re trying to think how customers are solving their problems outside of GCal. You may narrow your research to competitors (Outlook, for example), but many users keep physical instead of digital calendars. Knowing this, the PM might want to dive deeper into… Why are these potential users still using physical products? What is it about the physical calendar that the digital calendar doesn’t provide? Thinking outside of “products” that compete with us may give us a window into our user’s mind and help us solve for the real problem.

✅ Do

Explain what the current product looks like today and what its weaknesses are (and by product I mean, the elevator, ATM, car)

Explain how users are currently solving their pains

❌ Don’t

Spend too much time in this section

Overlook non-obvious ways in which a customer may be solving their problems today

Potential Features & Tradeoffs

What features or changes would improve those weak spots? Which one should we choose to build? Why?

✅ Do

Talk about a lot of ideas based on the use cases and pain points you decided to hone in to

Take a pause to ask if there are any major parts of the question where you’re gearing off (so you can go back and resolve them before you finalize your answer)

Depends on what you hear, either pivot and offer more ideas, or select one idea: “Awesome, I’m glad I’m headed towards the right direction. I would love to connect this back to my main goal [state the goal again clearly and concisely]… because of that goal, I want to pick this idea [state idea]”

Evaluate the tradeoffs and explain why you chose that solution. What could go wrong?

❌ Don’t

Be afraid of giving “crazy” ideas, that’s where the PM magic can happen

State too many solutions prior to honing in on one, or it might end up sounding like a laundry list of potential features

Just give 1–2 solutions at first, as that’s not a big enough list to select your one idea from

Product Vision [Optional]

State the vision in a compelling, inspiring way.

✅ Do

Give a 30–60 second pitch for your idea

Be crisp!

❌ Don’t

State the product vision if it is already clear

Success Metrics [Optional]

What does success look like for this product? How will we know we did the right thing?

You can choose from MANY metrics, but these are a few of my top picks:

  1. What percent of people in the segment are using my product?
  2. Does the person come back or want to use this again after their first time?
  3. How much money are we making from this feature?

✅ Do

Connect your success metrics back to the initial goal you stated

List your top 2–3 metrics that you’d like to keep an eye out for

❌ Don’t

List out metrics just for listing them out; you need to make sure that they make sense and are related to the problem at hand

Wrap Up

Give a summary of the whole process you went through and what your final answer is.

✅ Do

Keep this section short and sweet. You will probably be running out of time anyways!

❌ Don’t

Improve a product

The second type of question they may ask you in a product case interview is how you would improve an existing product. Some example questions:

  • Improve Amazon
  • Improve Google Hangouts
  • Improve Whatsapp

Here’s the process I follow to answer this type of question:

  1. Structure
  2. Product Goal
  3. Product Problems
  4. User Groups and Pain Points
  5. Solutions
  6. Implementation
  7. Validation
  8. Wrap Up

Below you can find details on how to approach each of those points.

Structure

Equivalent to the one in “Design a product” above. Walk the interview through what you’re going to do before doing it.

Product Goal

What is the goal of the product? What problem is it solving for the user?

Clearly define the different potential goals and delineate which one you’ll be focusing on. In an ideal world, everything you do as a product manager impacts one of these four goals (these are called different everywhere, but they should all sound familiar to you):

  • User acquisition: How do we recruit new users? Is there any customer segment we’re looking to onboard that is not already part of our product?
  • User adoption: How do we minimize user churn during onboarding? How do we get users invested in our product early on?
  • User engagement: What about the users already in the platform? How do we make sure they are having a better user experience? How do we make them use our platform more?
  • Monetization: How can we build a product that our users are willing to pay for?

Time permitting, you should discuss these goals with your interviewer, have a “strong conviction, loosely held” about which one(s) you should be focusing on, and validate this assumption together.

This shows that you have the ability to navigate levels effectively, to start from a problem and think high level how your work could affect the company as a whole.

✅ Do

Outline your understanding of how the product works and check with the interviewer that your understanding is correct

List out some goals and priorities of the product (are they focused on monetization? engagement?)

Think about how the product is currently designed… what does the product appear to prioritize?

❌ Don’t

Act as if you know everything even if you’re a power user of that product

Product Problems

Think about what could be some issues the product is facing right now. Some examples:

  1. Does it need to expand its user base? If so, should it broaden its user base by entering a new market, or should it expand in its existing market?
  2. Does it need to increase revenue? If so, is this about increasing revenue per user or about increasing the number of paying users?
  3. Does it need to increase user engagement?
  4. Does it need to increase conversions from visitors to registered users?

Make sure to select some problems related to the goal you already identified.

User Groups and Pain Points

Who is the target user? What are their pain points?

✅ Do

List all potential users/customers you can think of and explain how they would use the product

Select a user type

List user problems or problems we can solve for them in the given platform

Prioritize user problems (you can prioritize based on how painful these problems are for the user today)

❌ Don’t

List just one user, there’s always more than one

Forget the difference between users and customers

Solutions

How would you solve this problem? Discuss tradeoffs for each option.

✅ Do

For each of the user problems you have identified, generate potential solutions

Draw a table with two columns on a piece of paper. The first column should contain the user problems you have decided to solve. And the second problem should contain solutions to solve each problem.

Prioritize by grading each solution from low to high based on how much value they would deliver for the user, and how easy they are to implement.

❌ Don’t

Shy away from small, iterative improvements. They are equally as important as the bold, crazy ideas.

Implementation

How would you implement these solutions?

What are the bigger technical and business challenges?

How could you reduce the costs or risks associated with the solution? E.g., test out your solution on a smaller user base, or roll out a limited prototype.

Validation

How would you validate your solution?

What metrics would you gather to see if your product really worked?

Wrap Up

Equivalent to the one in “Design a product” above. Walk the interviewer through a summary of everything you just said in a crisp way.

Favorite product

The third type of question they can ask you in a product case interview is what your favorite product is. There’s many variations to this question, which is why you should be prepared with several products you like and why you like them. Here are the categories of products you should prepare for:

  • An online product
  • A physical product
  • A recently purchased product
  • A website

When answering this type of question, there’s no specific structure to follow, but here are some points you can try to hit on:

  1. Users and Goals: What are the primary user types? What are their goals? How does the product help users accomplish these goals?
  2. Strengths: For which metrics does the product excel? Does it have a lot of users? Does it have high engagement per user? What makes the product delightful to use? Why does the product excel in those things?
  3. Challenges: What is the main challenge the product faces? Is it struggling to get users to sign up? Is it struggling to convert free users to paid users? Why does the product struggle in those things?
  4. Priorities and Values: What does the product or company care about?
  5. Competitors: What are the product’s competitors? How does the product measure up to them?

A parting thought

There truly is no right and wrong solution to any one of these questions. The interviewer is evaluating you on how you break down complex problems into simple solutions, how you communicate, how you collaborate with others, how willing you are to change your ideas, how you approach vague situations, etc.

As long as you walk your interviewer through (almost) every thought that goes through your mind in the interview, you should do great.

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